1. Field of the Invention
The invention relates to a multicylinder internal combustion engine comprising intake valves and exhaust valves which are provided with at least one additional valve for each cylinder, a preferably tubular pressure container with a gas chamber into which extend ducts originating from the valves, so that gas can be exchanged between individual cylinders when the valves are actuated. The pressure container comprises a device for cooling the quantities of gas exchanged between individual cylinders.
2. The Prior Art
Brake systems integrated in vehicle engines, especially in utility vehicles, are gaining increasingly in importance because these systems concern additional brake systems that are cost-effective and compact. The increase in the specific output of modern utility vehicles, however, also requires an increase in the braking power to be achieved.
A four-stroke internal combustion engine with two groups of cylinders with four cylinders each is known from DE 34 28 626 A. Each cylinder comprises gas exchange valves and an additional exhaust valve. The additional exhaust valves are opened during the entire braking process in braking operations. Moreover, a throttle valve which is torsionally rigidly held on a shaft is arranged in the common exhaust port of the two cylinder groups. Its position can be influenced by a control rod by an actuating device. The disadvantageous aspect in this known system is the dependence on the speed, especially a relatively low braking output in the lower speed range.
DE 25 02 650 A further shows a valve-controlled reciprocating internal combustion engine in which compressed air is conveyed into a feed boiler via a compressed-air valve and is guided back during the starting via the same compressed-air valve for work output.
A decompression valve motor brake system is known in this connection from EP 0 898 059 A with which a compressed-air generator can be realized for all operating states of the internal combustion engine. A compressed-air tank of a compressed-air system is filled with compressed gas from the combustion chamber of the cylinders via a bypass line. One or more cylinders can be used for supplying the compressed-air system.
A motor brake system is known from EP 0 828 061 A in which a gas exchange is enabled between the individual cylinders via the common exhaust manifold. The gas exchange occurs via the exhaust valves of the six-cylinder internal combustion engine. The disadvantageous aspect in this motor brake system is, among other things, the relatively low achievable brake pressure.
GB 603 499 A describes a device for heat recovery from exhaust gas for internal combustion engines. A heat exchanger which is flowed through by a fluid is arranged in an exhaust manifold.
A multicylinder internal combustion engine of the kind mentioned above is known from AT 4.963 U1. It comprises a tubular pressure container with a pressure-control valve into which brake ports open which originate from brake valves, so that a gas exchange is enabled between the individual cylinders when the brake valves are actuated. In order to increase the braking power, the pressure container comprises a device for cooling the gas quantities exchanged between the individual cylinders, which device is integrated in the coolant circulation of the internal combustion engine. The cooling device comprises a cooling jacket which is flowed through by the coolant, which cooing jacket encloses the tubular pressure container. Although the braking power can be increased considerably by the cooling device, a further increase in the braking power would be desirable.
It is the object of the present invention to avoid such disadvantages and to further improve the cooling of the gas in the pressure container in an internal combustion engine.